Hello everyone. Me, Andy and Cory, my brother. We share the duties of keeping a 327 running for daily transportation. We have a small garage behind my house here in Hickory, NC. This problem 327 is in a 63 C10, 3 speed. My questions are, what should my idle timing be? I have engine at 820 rpms, manifold vac is steady at 15, holley 600 vac port capped, has a HEI, 350 heads and headers turbo mufflers.
I read on others threads anywhere from 8 to 12 BTDC. Our engine runs bad at 10 and is hard to get restarted after hot. Am I doing this right. 10 degrees on my digital timing light puts my balancer mark at Zero on chain cover tab? Thanks. Andy.

Have you proved your tdc mark on the balancer being true?
THe inertia ring on the balancer could have moved.
Also some dial back lights don't work accuratley with HEI.

I did the best I could. I got the coarse TDC by seeing where the Rotor was pointing to #1 instead of 180 off. Then using an indicator , I watched the peak rise and fall on the indicator dial. When I was at TDC on the indicator I was also on the ZERO mark on the balancer. I have to (for now) assume I am at TDC #1.
I may have a different problem if you want to read further down. Thanks for your response. I am 327 stupid but I do have some tools and the sun is out and its 50 degrees outside.

Make sure your mechanical advance inside the distrbuter is working properly. They can stick and freeze up so the advance wont work.

Thanks for your reply. I may have a different problem so I am going to do the "electrical" checks in just a little while. I want to stay mechanical for a few more moments because I found something strange.

and I am adjusting valves.
The method I am using is ,,,
At TDC, adjusting E-1, 3, 4, 8 & I-1, 2, 5, 7.
Then one turn to mark and adjusting E-2, 5, 6, 7 & I-3, 4, 6, 8.
I inspected all the rocker arms, balls, and nuts. I also ran all the pushrods around on a nice piece of glass to check for bends. All straight.

BUT there is weird problem on #7 Exhaust!!!!!!!!!!!!

When I check for ZERO backlash on #7 Exhaust, I can push the pushrod down about 0.140 before it stops. It has enough spring pressure to push me back up.

This feels like the spring inside of a lifter allowing me to fully seat the pushrod and then its strong enough to push the pushrod back up.
In other words, I could have zero backlash at one area, but then push the pushrod down 0.140 and obtain a zero backlash at that setting.
I can push my pushrod down, pretty easy, about .140 and it springs back up.
IS THIS NORMAL? I didn't have that happen on any other valve, just exhaust #7.

Another thing, it started to have a distinct PING or KNOCK on one cylinder. That's why I started with the valve adjustment first. Do I need to remove intake and start going thru the engine. It was a great running engine until last week. We started it and it started missing. Thanks yall.

Hello everyone. Me, Andy and Cory, my brother. We share the duties of keeping a 327 running for daily transportation. We have a small garage behind my house here in Hickory, NC. This problem 327 is in a 63 C10, 3 speed. My questions are, what should my idle timing be? I have engine at 820 rpms, manifold vac is steady at 15, holley 600 vac port capped, has a HEI, 350 heads and headers turbo mufflers.
I read on others threads anywhere from 8 to 12 BTDC. Our engine runs bad at 10 and is hard to get restarted after hot. Am I doing this right. 10 degrees on my digital timing light puts my balancer mark at Zero on chain cover tab? Thanks. Andy.

When you say it runs "bad" at 10 BTDC, exactly what do you mean? Are you talking about the performance on the road is bad or it's bad because it's hard to start, or ?

Does it run better at a lower or higher idle timing (idle timing is called initial timing)?

Besides the timing at idle you need to know the total timing (total timing is idle timing plus mechanical advance, but not counting vacuum advance), and at what rpm the total timing is all in by. To check the timing, you first have to remove the vacuum hose to the advance canister and plug the line so there's no vacuum leak. Only then can you get a reliable timing reading.

The vacuum advance should cause the idle speed to increase along with the timing seen with the timing light when you hook it up to a full-time vacuum source at the carb. A full-time vacuum is called "manifold" vacuum. Hooking the vacuum advance to manifold vacuum is usually preferred over ported vacuum. Ported vacuum is not there at idle, only there when the throttle blades are opened some.

With the valve adjustment on the lifter that you can push down, you want to set the preload with the lifter all the way at the top of its travel. If there's noise from that lifter after it's adjusted correctly, you may need to go into this deeper.

With the valve adjustment on the lifter that you can push down, you want to set the preload with the lifter all the way at the top of its travel.

Thanks for the reply. I need to study everything you said before I answer you back. However, I am working the problem related to the last thing you said.
Do you mean,,,After the valve is adjusted, I should or should not be able to push the rocker down this extra .140 travel? Its pretty easy to push down.
Do I need to remove all clearances (this .140) and then adjust the valve? Thanks.

Thanks for the reply. I need to study everything you said before I answer you back. However, I am working the problem related to the last thing you said.
Do you mean,,,After the valve is adjusted, I should or should not be able to push the rocker down this extra .140 travel? Its pretty easy to push down.
Do I need to remove all clearances (this .140) and then adjust the valve? Thanks.

After the lifter is adjusted you still will be able to push it down.

For whatever reason, that lifter is not filling or is not retaining the oil that it uis supposed to fill with when the engine is running.

If the lifter is plugged and is unable to fill with oil when the engine is running, the lifter will be noisy, performance will be off and the valvetrain (cam, lifter, p-rod, rocker arm) could be damaged.

Sometimes the lifter can be removed, taken apart and cleaned, then returned to the engine. You can't usually get away with replacing a lifter w/a new lifter on a cam that has already been used because the lifter and cam wear in together.

For whatever reason, that lifter is not filling or is not retaining the oil that it uis supposed to fill with when the engine is running.

If the lifter is plugged and is unable to fill with oil when the engine is running, the lifter will be noisy, performance will be off and the valvetrain (cam, lifter, p-rod, rocker arm) could be damaged.

Sometimes the lifter can be removed, taken apart and cleaned, then returned to the engine. You can't usually get away with replacing a lifter w/a new lifter on a cam that has already been used because the lifter and cam wear in together.

PERFECT PERFECT! Thanks. I adjusted it at the top. And like you said, after its adjusted, I can still push it down(and it springs right back). I started the engine and it runs now WITHOUT THAT DEADLY CLICK. I thank you again.
It does seem that I have a lifter that is not staying full of oil. I guess its removing the intake and whatnot, do you agree?
I will worry about timing after I get things back together with new lifter(or rebuilding lifter), or all new lifters. Im just happy to see what may have been my problem all along.

Colbalt327 Thanks again. We decided to go with the pull the manifold and do the lifters job. I am still trying to figure out what engine specs I have. The engine block number is 3782870, its got 350?, heads, and I dont know whats inside. Last week it ran like a 60's rail dragster. We **n luv it and dont want to damage it.

I think I will get a full set of lifters at the Chevrolet dealership. I also saw a little bit of damage on 2 pushrods right at the oil hole so they will get replaced too. But I wonder if I should loose my cast iron intake and go to aluminum? I like the cast iron intake.

Also about the vacuum for the distributor. There are two ports I question. My distributor is hooked up to "A". Should it be hooked up to "B" instead? Thanks.

............ You can't usually get away with replacing a lifter w/a new lifter on a cam that has already been used because the lifter and cam wear in together..

I had to stop and slowly re read what you said. I understand about the cam and lifter wearing as one. I will attempt the cleaning and restoring my original lifter but if it's toast, then I guess I would have to replace it and hope for the best?

I had to stop and slowly re read what you said. I understand about the cam and lifter wearing as one. I will attempt the cleaning and restoring my original lifter but if it's toast, then I guess I would have to replace it and hope for the best?

Likely cleaning it will be all it needs. In an extreme case where the plunger is toast, I recommend replacing the plunger and reusing the original lifter body. The link I meant to give you is here. It has more detail.

If the foot of the lifter is too worn, replacing the lifter w/a new one will likely result in a ruined cam and ground up metal all through the engine which can take out the bearings, or worse. In that case, replacement of the cam and all the lifters is called for.

Colbalt327 Thanks again. We decided to go with the pull the manifold and do the lifters job. I am still trying to figure out what engine specs I have. The engine block number is 3782870, its got 350?, heads, and I dont know whats inside. Last week it ran like a 60's rail dragster. We **n luv it and dont want to damage it.

I think I will get a full set of lifters at the Chevrolet dealership. I also saw a little bit of damage on 2 pushrods right at the oil hole so they will get replaced too. But I wonder if I should loose my cast iron intake and go to aluminum? I like the cast iron intake.

Also about the vacuum for the distributor. There are two ports I question. My distributor is hooked up to "A". Should it be hooked up to "B" instead? Thanks.

OK, just saw this. Before ordering up a set of lifters that you may not need, get the one bad one out and take it apart and see what you can see.

I would much prefer you to use just the plunger from a new lifter in your old lifter body (replace the guts, in other words), than to try to get away with using a new lifter (or a set of new lifters) on a used cam. Fixing the original lifter by cleaning is the best case. Next to that, replacing the guts of the old lifter, then next would be to use only ONE lifter to replace the unrepairable lifter. Last choice, and one I just cannot recommend under ANY circumstances, is to replace ALL the lifters with new ones.

The reason is pretty simple, really. If one lifter is replaced, only one lobe and one lifter will be ground up into the motor oil to act as sandpaper to ruin the engine. If the entire set of lifters are replaced, the chances are more than one lifter and cam lobe will fail, and the amount of sandpaper in the engine will be a lot greater.

If it turns out that the bad lifter is trashed on the bottom where it contacts the cam, consider the cam trashed, too. In that case, replace the cam AND lifters as a set. It sounds expensive, I know. But it's less expensive than replacing the lifter(s), then having to tear the engine back down again to clean it of the ground up metal caused if/when the cam and lifter fail, then having to replace the lifters a second time along with a new cam, including another set of gaskets and more oil and filter.

Intake:
An aluminum intake would be a good addition to your engine. Especially if you're using an adapter to mount a Holley carb on an intake made for a spreadbore Q-jet carb.

If your truck has a mild cam I might go with an Edelbrock Performer EPS (p/n 2701 for satin finish, for '86-back heads).
If the cam is bigger, I'd use a non Air Gap Edelbrock RPM (p/n 7101, satin, for '86-back heads).

BUT before buying an intake, you need to see what heads you have. The bolt holes changed on '86-'95 heads, then again on '96-up heads.

Having 15 inches of vacuum could mean you have a bigger than stock cam, or it might need more initial timing. It might even have a vacuum leak. Does it have a "lope" to the idle, or is it very smooth?

Ignition:
You are hooked up to ported vacuum. It might run better using manifold vacuum (the vacuum port on the baseplate). Try it and see. The problem is sometimes the vacuum advance gives too much advance. Usually 10 to 12 degrees added vacuum advance is about right if you're using manifold vacuum and a good amount of initial timing. It won't hurt to try using manifold vacuum, though. You will find that it will increase the idle speed, so be ready to lower it and to readjust the idle mixture screws to get the highest idle speed, or highest vacuum if you have a gauge.

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